注解

/**
* 注意使用Retention，只有指定Retention为RetentionPolicy.RUNTIME
* 时在运行时才能获得注解信息
*/
@Retention(value = RetentionPolicy.RUNTIME)
public @interface Test {
    String name() default "tian";
    int age() default 12;
}

//使用自定义注解
@Test(name = "song", age = 27)
public class Person {
}

//利用反射获取注解信息
public static void main(String[] args) {
    Annotation[] annotations = Person.class.getAnnotations();
    for (Annotation annotation : annotations) {
        if (annotation instanceof Test) {
            log(((Test) annotation).name());
        }
    }
}